This invention relates to an ultrasound system and method for imaging, and in particular, for assisting in medical diagnosis.
Ultrasound imaging may be used to assess the health of tissue within the body. Methods that may be used for this assessment include Doppler based methods, such as Doppler Tissue Imaging. In this method, Doppler based processing is used to measure the velocity of tissue within a region being examined. Knowledge of tissue movement, especially in relation to the motion of the neighboring regions, can indicate tissue health. This method can be used to examine the health of an organ, such as the heart.
Perfusion measurements also provide diagnostic information. Perfusion is the blood flow per unit of tissue mass that supplies the tissue with oxygen and nutrients (volume/(time*mass)). Ultrasound systems may also be used to estimate perfusion. Methods that attempt to estimate perfusion include measuring the wash in and wash out times of contrast agents injected into the blood stream at a region of interest as the contrast agent enters and exits the region of interest.
Neither the tissue motion nor perfusion methodologies discussed above provide a complete assessment of tissue viability. Viability of tissue is the ability of the tissue to recover and function normally. Therefore, it is desirable to provide an ultrasound method and apparatus for tissue viability imaging.